Automatic telephone system



F. KESSLER AUTOMATI C TELEPHONE SYSTEM Apri l13, 1937.

Filed April '1, 1935 I INVENTQR. FRANK KESSLER ZM ATTORNEY.

Patented Apr. 13, 1937 UNlTED STATES PATENT OFFICE AUTOMATIC TELEPHONE SYSTEM Application April 1, 1935, Serial No. 14,049

19 Claims.

This invention relates to automatic telephone systems in general, but relates more particularly to small systems of the character commonly known as isolated private automatic exchanges.

These systems are, as a rule, privately owned by individuals or corporations and are installed in factories and other establishments for providing local service between a small number of local telephone lines.

The main object of the invention is the provision of means for providing a new and improved divided ringing arrangement in order to increase the number of subscribers capable of being served by a system of this type without materially increasing the cost of the equipment.

Other features of the invention relate to the improved circuit arrangements for accomplishing the above in a finder-connecter link circuit comprising a numerical forward selecting switch for connecting with and signaling a called subscriber and a non-numerical line finder switch for finding the calling line.

The drawing diagrammatically shows three subscribers lines together with their individual cut-off relays l, 64, and 94 and a finder connecter link circuit. The line circuit of each subscribers line terminates in the banks of the finder such as the finder F and in the banks of the connecter such as the connecter C. The

automatic substations A and A are connected on the same line and have their ringers normally connected to opposite line conductors of this line. Substations B, C, and C are similar to substations A and A and have their ringers normally connected to one of their line conductors as diagrammatically illustrated. Each of the substations has the usual signaling, talking, and switchcontrolling instrumentalities.

The mechanism of the finders, such as F, and the connecters, such as C, is of the well known rotary type, commonly used for rotary line switches, and the wipers of which move in a forward direction only and remain in the positicn last used. The circuit details of the connecter aresomewhat different from the finder in that the wipers of the connecter are directively operated to a called line and are automatically restored to normal position after termination of the conversation.

In the case illustrated, applicant has elected to show a system having a maximum of twentytwo local lines with forty-three subscribers having telephone numbers 2-8, 11-18, 91-99, 191-199, 901?9.05, and 1901-1905. .The substations having called numbers. 2.to 8, inclusive, and 11 to 18,

inclusive, terminate in the first eight bank contacts accessible to the wipers of the conne'cters, the substations having the call numbers 91 to 99, inclusive, and 191 to 199, inclusive, terminate in. the tenth to the eighteenth bank contacts ac- 5 cessible to the wipers of the connecter, and the substations having the call numbers 901 to 905, inclusive, and 1901 to 1905, inclusive, terminate in the twentieth to the twenty-fourth contacts accessible to the wipers of the selectors. The ninth and nineteenth bank contacts are left dead, while the twenty-fifth contact is used for normal position of the connecter wipers. The line terminating in the first set of bank contacts accessible to the connecter wipers has its test conductor Hi4 extending from relay 64 connected to a normally open contact in each of the connecter switches, while the test bank contacts accessible to the test wiper of each connecter are individually connected by a conductor I03 to an open 20 contact opposite a corresponding one of the previously mentioned contacts. The remaining bank contacts in the connecter switch are multipled and connected in the usual manner between switches.

The subscribers cut-off relays such as 4, 64, and 94 and relays l4 and 23 are two-step relays which close their contacts marked I in their first step and their contacts marked II in their second step. Relays l2, l1, and I9 are slow to operate relays which are also appreciably slow to release. Relay I3 is equipped with a copper sleeve around its core which renders this relay also slow to release.

Having briefly described the apparatus involved in a system of this type, a detailed description of the operation will now be given. For this purpose, it will be assumed that subscriber A wishes to obtain connection with subscriber C. When subscriber A removes his receiver to initiate a call a 40 circuit is completed for energizing two-step relay 4 in its first step as follows: from ground by way of armature 5, conductor 2, substation loop at the calling substation A, conductor 1, armature 1, through the resistance winding of relay 4 and the upper operating winding of relay 4, to battery. Due to the resistance winding, cut-off relay 4 operates and closes only armatures 6 and 3. At armature 6 relay 4 connects the battery through its upper winding to the test contact accessible to wipers 9 of the finders F to mark this line as a calling line. At armature 3 relay 4 completes a. circuit for energizing the start relay I2 of an'idle' finder connecter link. The circuit for energizing relay l 2 may be traced as follows: from grounded armature I I by way of armature 3, common start conductor 25, through the winding of relay I2, springs 42, normal position bank contact and wiper 62, interrupter springs of motor magnet 2|, armature 58, armature I5 and resting contact, and through the winding of connecter motor magnet 2| to battery. Due to the high resistance of relay I2, motor magnet 2| is not energized over this circuit, but the start relay I2 energizes to start the finder in its hunting operation. In case this finder connecter link is busy, then springs 42 would be open and Wiper 62 would not be in normal position; therefore, the start circuit would extend to the next finder connecter link by way of armature 3| and conductor 24. Returning now to when start relay I2 was energized in response .to subscriber A initiating a, call, said relay at armature 30 prepares the test circuit for relays I4 and I5, at armature3| opens the circuit extending to the next finder connecter link, at armature 4 33 prepares'a circuit for the lower winding of relay I5,'and at armature 32 completes a circuit extending from armature 43 and its resting contact for energizing the finder motor magnet 20. Magnet energizes to position its pawl preparatory to stepping the wipers of the finder and near the end of its stroke closes armature 34 to complete a circuit for energizing relay I5 by way'of armature 33. Relay I5 energizes and at armature 43 opens the circuit extending to magnet 20 which deenergizes and operates the wipers of the finder'one step. The deenergization of magnet 20 also opens the circuit of relay I5 at armature 34 and the latter relay deenergizes to again close the circuit to the motor magnet 20. This interaction between step relay |4, armature 3ll, test'wiper 9 and engaged bank contact, armature 6, and through the upper winding of cut-ofi relay 4 to battery. Re-

" lay I5 is held energized over this circuit in order to'prevent the finder motor magnet from energizing to step the wipers another step. Cut-oil relay 4en'ergizes in its second step over the-above traced circuit. The two step relay I4 energizes in its first step over the above-traced circuit to close only armature 40, which completes a circuit for energizing slow to releaserelay I3 by way of the working contact of armature 43. Slow to release relay I3 at armature 35 opens a point in-the restoring circuit of the connecter C'at itsresting contact, and atits working contact prepares a point in the connecter testing circuit. At armature 34 relay I3 grounds the hold conductor 29 and-likewise completes a circuit through-the lower winding of relay |4-to energizetwo-step relay I4 through its second step. At armature 3] relay I3 prepares a point in the impulsing circuit'to the connecter motor magnet and at armature 36 prepares a point in the talking circuit'as well as preparing a 'point in ,the impulsing circuit for relay the upper winding of relay I5 and likewise opens the original energizing circuit of relay I4. At armature 39 relay I4 grounds test wiper 9 to maintain the combined line and cut-off relay4 in energized position and to maintain the calling line busy. At armature 4| relay I4 prepares a circuit for the series relay I6, .and at armature 42 opens the circuit of start relay I2. At the normally closed springs controlled by armature 38 relay I4 opens the test circuit including the upper winding of relays I4 and I5 but these relays do not deenergize at this time because relay I4 is held over its lower winding while the calling subscriber's loop is now connected in bridge of both windings of line relay I5 to prevent its deenergization. Line and cut-ofi relay 4, upon energizing in its second step in response to the grounding of wiper 9, at

armatures' 5"and I disconnects ground and the connects the start lead conductor to conductor 24 extending to the next finder connecter link. At armature 32 relay I2 opens the circuit to finder motor magnet 20 and at armature 33 opens a point in the circuit "to the lower winding of relayI 5.

All of the operations just described have taken place responsive to the subscriber at substation A removing his receiver, and at this time dial tone is transmitted from the normal bank contact v of connecter C by way of wiper 60, armatures I2 and 44 and 5|, condensers C to the upper talking conductor, and thence over the calli'ngsubscribers loop in the well known manner.

SubscriberA may dial the number of the desired subscriber's line, in this case No. 96, since subscriber C is the desired subscriber and such subscribers lineterminates in the fifteenth set 01 opened at armature 43 and its working contact,

but saidrelay, due. to the copper sleeve around its core, maintains its armature attracted during the impulsing period. Each time relay I5 deenergizes, a circuit may be traced from grounded armature 43 and its resting contact, armature 31,

' traced circuit extendsby way of armature 4| and the lower winding of; series relay I6 for energizing the latter relay. Relay I6 atarmature 44 opens a point in the dial tone circuit, at armature 45 opens a point in the test circuit as well as preparing the circuit for busy relay I8, at armature .46 short circuits its upper winding to make this relay slow to deenergize so that it will be maintained energized during the impulsing period, and at armature 4I shunts armature 53. After the first impulse line relay I5 reenergizes and opens the circuit of magnet 2 I which releases and steps the wipers of the connecter one step. The remaining impulses of the first digit operate the line relay I5 and magnetlI in the manner set forth to position the wipers 60 to 63, inclusive, on the ninth set of bank contacts. Since these contactsar'e left dead the wipers merely come to rest thereon, until the second digit is dialed.

armature 53, armature58, armature I5 and rest: 7

'ing contact, and through the winding ofmotor Responsive to subscriber A dialing the second digit, or digit 6 in this case; line relay l5, series relay 5, and magnet 2| operate in the same manner as previously set forth to position the wipers 5 on the fifteenth set of bank contacts, or the contacts terminating the line of substation C.

Assuming that the line of substation C is busy, then wiper 6| will encounter a ground connection on the fifteenth bank contact placed thereon 10 by a finder or connecter of another finder connecter link. 'In this case busy relay I8 is energized over a circuit extending from the busy grounded contact, wiper 6|, armature 45 and its working contact, and through the winding of busy relay I8 to battery. Busy relay I8, upon energizing, at armature 52 prepares a locking circuit for itself, at armature 53 opens a point in the impulsing circuit to magnet 2|, and at armature 5| completes a circuit for transmitting busy tone over the talking conductors and condenser C to subscriber A. A short time after the transmission of the last digit, series relay l6 deenergizes and at the normally closed contacts controlled by armature 45 completes the locking circuit of busy relay l8 as follows: from grounded armature 51, armature 35 and working contact, armature 52 and working contact, through the normally closed springs controlled by armature 45, and

through the winding of busy relay IE to battery.

When subscriber A hears the busy tone such subscriber will replace the receiver and release the connection in the same manner as will be described hereinafter.

Assuming now that the line of substation C is idle instead of busy, then wiper 6! will not encounter a grounded contact, and, when relay l6 deenergizes after the impulsing period, a circuit may be traced for energizing the switching relay |9 to close its armatures 55 and 56 and for energizing combined line and cut-off relay 94 in its first step to close armature 96 as follows: from grounded armature 57, armature 35 and working contact, armature 52 and resting contact, through the lower winding of switching relay I9, resting contact and armature 45, wiper 6|, fifteenth bank contact, conductor I I3, and through the upper winding of the two-step line and cuton relay 94 to battery.

Cut-01f relay 94 closes only its armature 96 and switching relay I9 is adjusted to close only its armatures 55 and 56 at this time. When relay I9 closes its armature 55 a circuit may be traced for energizing relay 94 in its second step as follows: from grounded armature 55, wiper 6|, and thence over the previously traced circuit through the upper winding of relay 94. Relay 94 is fully operated over this circuit to operate its armatures 95 and 91 to disconnect the line conductors Ill and H2 from ground and the windings of relay 94. The operation of armature 99 prevents the operation of relay 94 from starting an idle finder connecter link. At armature -56 relay 9 completes a locking circuit through its upper Winding 65 from grounded hold conductor 29 and for fully operating its remaining armatures. Relay l9, upon fully operating, at armature 51 opens a point in the original energizing circuit of relay l9 as well as opening a point in the restoring circuit of the 70 connecter, at armature 58 opens a point in the impulsing circuit to magnet 2|, at armatures 54 and 59 closes points in the talking circuit to the called line and at armature 53 connects interrupted generator to the called line as follows:

75 from generator lead by way of armature 53, resting contact and armature resting contact and armature 48, armature 54, wiper 66, conductor I 2 and through the switchhook springs and ringer at substation C to ground. When subscriber C answers by removing his receiver, ring-cut-off relay I1 is energized over the substation loop from generator over the previously traced circuit and from thence through the substation 100p, conductor wiper 63, armature 59, armature 50 and resting contact, armature l5 and resting contact, and through the lower winding of cut-off relay IT to battery. At armatures 48 and 50 relay disconnects the ringing circuit and completes the talking circuit, and at armature 49 completes a locking circuit through its upper winding to 1 grounded-hold conductor 29. The calling subscriber A and called subscriber C are connected over the heavy talking conductors, each subscriber receiving talking battery from the windings of line relay |5.

After conversation and responsive to subscribers A and C both replacing their receivers, line relay |5 deenergizes and at armature 43 opens the circuit of release relay |3 which deenergizes after a short interval. At armature 34 release relay disconnects ground from hold conductor 29 whereupon relays M, H, and. I9 deenergize. At armature 35 relay l3 opens the locking circuit of busy relay |8 in case the latter relay is energized, and also prepares a self-interrupting circuit for motorv magnet 2|, and at armature 36 opens a point in the talking circuit. Relay 4, upon deenergizing, at armature 38 opens a point in the talking circuit as well as preparing its original energizing circuit, at armature 39 disconnects ground from wiper 9 to cause the deenergization of line cut-off relay 4 to make the calling line accessible to other calls, at armature 49 opens a further point in the circuit of relay l3, at armature 4| opens a further point in the circuit to series relay l6, and at armature 42 prepares a point in the original energizing circuit of start relay I2. Line and cut-off relay 4, upon deenergizing, restores its armatures to normal position. Switching relay l9, upon deenergizing, at armature 53 opens a point in the ringing circuit, at armatures 54 and 59 opens further points in the talking circuit, at armature 57 connects ground to the multiple bank contacts accessible to wiper 62 to cause the connecter wipers to be restored to normal, at armature 55 disconnects ground from conductor 3 to deenergize line cut-off relay 94, at armature 56 opens a point in its own locking circuit, and at armature 58 closes a self-interrupting circuit to motor magnet 2|. Relay 94, upon deenergizing, restores its armatures'to normal position. Ring cut-01f relay I'l, upon deenergizing, atarmatures 48 and 59 opens further points in the talking circuit,.and at armature 49 opens a point in its own locking circuit. Motor magnet 2| is now'operated over the following circuit: from ground by way of armature 51, armature 35 and resting contact, the multipled bank contacts engaged by wiper 62, interrupter springs of magnet 2|, armature 58, armature l5 and resting contact, and through the winding of magnet 2| t battery.v Magnet 2| operates like a buzzer over the above traced circuit until wiper 62 no longer engages a grounded contact, at which time the wipers of the connecter stop and remain in normal position, or the position shown in the drawing. The wipers of the finder remain in the position last used, and, therefore, when the connecter wipers reach their normal position the finder connecter link is available for another call.

The operation of the finderconnecter link for subscribers having telephone numbers 2 to 8, inelusive, is the same as that previously described with the exception that only one digit is dialed instead of two. In order to call asubscriber havingtelephone numbers901 to 905, inclusive, three igits are dialed by the calling subscriber to set the connecter on dead bank'contacts responsive to the first two digits, after which the last digit may be dialed to connect with the desired sub:

scribers line. a

The foregoing describes how subscribers A and C, having their ringers connected to positive line conductors and ground, are called and signaled. Subscribers having their ringers connected to the negative line conductor and ground may be called and. signaled in case the first digit dialed is digit 1. In order to describe how such subscribers are called and signaled it 'will be assumed that subscriber A wishes to talk to subscriber C connected to the same line as substation C. In response to subscriber A removing his receiver relay '4 operates in its first step, start relay l2 energizes, finder motor magnet 20 and relay I5 interact inthe same manner as previously described to step the wipers of the finder to the calling line. When wiper 9 encounters the calling potential relays 4, l4, l5, and I3 operate as previously described to connect the calling line in bridge of relay: I5 at which time the calling subscriber hears dial tone. In order to call substation C", subscriber A first dials digit 1 to cause relay l5 to transmit a single impulse to the connecter motor magnet 21 whichsteps .wi-

' pers of the connecter to the first bank contact lower winding of switching relay I9, resting contact and armature 45, wiper 6|, in engagement with its first contact, over the individual conductor I03 -which is individual to this switch, armature 14, and through the winding of relay 22 to battery. Armature springs 13 are adjusted to make before springs "break, with the result that relay 22 is locked energized to. hold conductor 29 through its upper winding before its initial energizing circuit is broken at armature 14. At armature H relays 22 prepares the circuit for r'ing'cut-oif relay H, as Well as opening the ringing circuit to the upper talking conductor. a

At armature 12 relay 22 opens the circuit extending. to wiper so that if line No. 11 is in use there will be no disturbances, at armature 15 transfers the impulsing circuit from magnet.

2| to two-step relay 23, and armature l6 prepares the circuit for connecting interrupted generator to the lower talking conductor. Even if line No. 11 is busy, busy relay I8 is not energized at this time because of the individual and common wiring on the test contact and the test conductor of line II, as will be more fully described hereinafter.

Subscriber A now dials the second digit or digit 9. In thiscase, since the digit 1 was dialed for the first digit, thefirst impulse of the second digit operates two-step relay 23 and the remaining pulses of this digit thereafter operate the connecter motor magnet 2| to move the wipers of the connecter eight steps to stop the wipers on the ninth bank contact which is dead. In response to dialing digit 9 relay l5 deenergizes nine times. On thefirst deenergization of line.

relay 15 a circuit for operating relay '23 in its first step may be traced as follows: from ground by way of armature 43 and resting contact, armature 31, armature -53, armature 58, armature 15 and its \working'contaot, armature 8B and 5' resting contact and :through the lower winding of relay 23 to battery. Series relay l6 likewise energizes in its previously traced multiple circuit. Relay 23 operates only armature '18 in its first step to connect grounded hold conductor 29 to its upper winding which at this time isshort circuited from ground at armature 43. Due to this short circuit around its upper winding relay 23 is'operated only in its first step. When line relay l5 reenergizes after the first pulse of the, second digit the short circuit around the upper winding of relay 23 is removed and relay 23 thereupon energizes in its second step. At armature 1'I relay 23 prepares a point in the cir-' cuit to wiper '60, at armature I9 prepares a temporary test circuit for line H, and at armature 80 transfers the impulsing circuit back to the connecter motor magnet 2| so that the remaining impulses (eight in number) now operatemag the fifteenth bank contact terminating the line.

of substations C and C". Busy relay' It! operates in'the same manner as previously described in case the line is busy and in case the line is idle switching relay I 9 energizes as before whenrelay.

l6 energizes.

Assuming that the called line is idle, then since relays 22 and 23 are in energized position, the energization of switching relay l9 connect's'in terrupted generator to the lower talking conductor as follows: from interrupted generator,

armature 53, working contact and armature I6, resting contact and armature 50, armature 59;

wiper, 63 in engagement with the bank contact.

terminating conductor HI and over said conductor through the switchhook springs and ringer at the substation C to ground. The ring-back circuit for indicating the application of generator to the called line extends inpthis case through the ringing condenser RB when generator, is applied to the lower talking conductor, while in the cases when generator is applied to the upper talking conductor the ring-back tone extends by way of the upper talking conductor armatures.

i2, 44, and BI and through the conductor C. When the called subscriber C answers a' circuit is completed for energizing ring cut-ofi relay H from generator over the previously traced ringing circuit and from thence through substation loop of subscriber C, conductor H2, wiper 60, arm'a-' ner as previously described. a

From the foregoing it will be seenthat in order to call two subscribers on the same line, such as subscribers C and 0', Nos. 96 and 196 are dialed. Subscriber C is signaled over'the positive line conductor, while subscriber C is signaled over the negative line conductor. This change in signaling over either line conductor is brought about dependent upon the first digit dialed. That is, only when the first digit dialed is digit 1, then signaling current is transmitted over the negative line conductor. When digit 1 is dialed for the first digit, the first impulse of the second digit causes the operation of relay 23 while the remaining impulses of the second digit steps the wipers of the connecter. The number of steps taken by the connecter wipers are therefore the same for connecting with and signaling either party on the same line. Since the connecter C has a 25-point bank and the ninth and nineteenth bank contacts are dead with the twenty-fifth position being used as a normal position, the capacity of the connecter banks is twenty-two lines. Twenty-one of these lines may be provided with two substations while only one substation is connected to the line terminating in the first set of bank contacts. therefore provides service for forty-three substations. The following chart shows the call number of the different substations and the bank contacts to which the lines of such substations are connected.

Bank contact Telephone N 0.

Telephone No.

1 11 2 2 12 3 3 13 4 4 14 5 5 15 6 6 16 7 7 17 8 8 18 9 Dead 10 91 191 11 92 192 12 93 193 13 94 194 14 95 195 15 96 196 16 97 197 17 98 198 18 99 199 19 Dead 20 901 1901 21 902 1902 22 903 1903 23 904 1904 24 905 1905 25 Normal position In case a subscriber dials digits 1 and 1 to call subscriber B the finder and connector operate as previously described to step the wipers into engagement with the first set of bank contacts. In this case, since the first digit dialed was digit 1 relay 22 is energized. Relay 23 energizes in response to the second digit to complete the circuits for relays I9 and 64. The wipers in this case are not stepped off of the first set of bank contacts because the second digit comprises only one impulse which operates relay 23. The circuit for operating relays I9 and 64 may be traced as follows: from ground by way of armature 5I, armature 35 and working contact, armature 52 and resting contact, through the lower winding of switching relay I9, resting contact and arma ture 45, wiper 6 I, individual conductor I03, armature I9, common conductor I04, and through the upper winding of relay 64 to battery. Relay I9 at armature 55 connects direct ground to the The system upper winding of relay 64, thereby causing relay 64 to operate its armatures through its second step to disconnect ground and the windings of relay 64 from line conductors IOI and I02. At armatures 53, 54, and 59 relay I9 connects interrupted generator to the lower or negative line conductor to ring subscriber B over conductor IIII in a manner similar to that previously described. When subscriber B answers ring cut-off relay II operates as before to disconnect ringing current and complete the talking circuit. The finder connecter link is released in the same manner as previously described when both subscribers replace their receivers.

In case the line of substation B is busy when called, then the busy relay I8 is energized from ground on common conductor I04 which ground is placed on conductor I 04 by way of armature 39 and wiper 9 of the engaged finder connecter link or by the grounded armature 55 and Wiper BI of the busy engaged connecter switch and thence by way of conductor I 04, armature I9, individual conductor I03, wiper 6|, armature 45 and Working contact, and through the winding of busy relay E8 to battery. The busy tone is transmitted to the calling subscriber and the finder connecter link is released in the same manner as previously described.

The busy relay I8 is not energized when the connecter wipers stop on the first bank contact in response to the first digit, because no circuit is completed for such relay even if the line of substation B is busy. This is due to the wiring of the connecter switch banks wherein conductors, such as conductor I03 are individual to each switch and are not multipled between switch banks while conductor I04 is common to all the connecter switches and terminals in an armature I9 on each connecter. Since contacts I9 are not closed in response to the first digit the circuit to the busy relay I8 is held open thereat when wiper 6| stops at bank contact I in response to the first digit. This, therefore, enables the connecter wipers to temporarily stop on the first set of bank contacts without interfering with the busy connection or with the connection being set up.

Having described the invention, what is considered to be new and is desired to have protected by Letters Patent will be set forth in the following claims. 7

What is claimed is:

1. In a telephone system, an automatic switch including wipers and a switchbank, a party line terminating in said switchbank, the call number of the first party on said line being dependent upon the bank contacts said line terminates in, the call number of the second party on said line being the same as the first party but with a predetermined digit prefixed thereto, means for operating the wipers of said switch into engagement with the bank contacts terminating said line in response to dialing either one of said call numbers, and means for selectively signaling either party on said line dependent upon the call number dialed in extending the connection to said line.

2. In a telephone system, an automatic switch including wipers, a party line terminating in said switch, a source of signaling current, means for operating said wipers into engagement with said line at different times by a different number of directively controlled operations each time by a different number of steps, and means for assomat ng said source with one or the other of said j wipers-to selectively signal a desired party on said line'dependent upon the number of directively' controlled operations by which the wipers are operated to connect with said line.

i 3. In a telephone system, party lines, an automatic switch having a pair oi line wipers for extending a connection to called party lines, means for directively operating said wipers in one, two, three; or four directive movements to complete 10 current; means for connecting said source to one of saidwipers in case the calledline wasconnected within one, two, or three directive movements, and means for connecting said source to the other of said wipers in case the called line was connected with one, two, three, or four directive movements.

'4. In a telephonesystem, a party line having a pair ofline conductors, a first and a second sub- 2 station on said line, an automatic switch having wipers, means for directively operating said wipersin one'or two directive movements to complete connections to said line, a source of signalling current, means for'connecting said source to one of said line conductors of said line to operate the ringer ofthe first substation in case the called line was connected with in only one directive movement, and means for connecting 7 said source to the other of said line conductors of said line to operate the ringer of the second substation in case said line was connected with in two directive movements. I n

' 5. In a telephone system, party lines, an automatic'switch' having a pair'of line wipers for extending a connection to a called party line, means for. directively operating said wipers inone, two, three, or iour directive movements to complete connections to said lines, a source ofsignalling current, and means for connecting said source to one of said wipers in case the called line was connected with in one directive movement, for connecting said source to either one of said wipers I inv case the called line; was connected with in one v two, or three directive movements dependent upon the preliminary directive operation of said wipers, and for connecting said source to the other of said wipers in case the called line'is connected with in four directive movements.

6. In a telephone system, a party line, a single level forward operating non-releasing switch ineluding a pair of line wipers, means for operating said wipers to extend a connection to said line, a source of signalling current normally associated with. one of said wipers, and means responsive to the first operation of said wipers in case such first operation corresponds 'toa particular digit for transferring said source into association with the other wiper.

7.In a telephone system, party lines, a party 60 line connecter switch responsive to one dialed digit comprising a complete called number and also responsive to a plurality of dialed digits in other called numbers to extend connections to said lines a source of signaling current, and means dependent upon the first digit called in the called number for connecting said source to one Or the other line conductor oirthe called line.

8. In a telephone system, party lines, an auto- M. matic switch including a pair of line wipers, meansresponsive to dialed digits in a called telephone number for operating said wipers one step for each impulse into engagement with a called one of said lines, a source of signaling current .i normally associated with the first of said wipers, 75 means operative in case the first digit dia ed is a connections to said lines, a source of signaling predetermined digit, for associating said signaling source with the second of said wipera-and means operated by the firstimpulse of thesec 0nd digit in case said last means is operated for absorbing the first impulse of the second digit whereby said wiper stepping means steps said wipers in response to only the remaining impulses of the second digit, r

9. In a telephone system, a two-party line, the call number of the first party on said line comprising a given number, the call number of the second party on said-line comprising a predetermined number plus said given number, an automatic switch including wipers, means responsive to dialing said given number for operating said wipers one step for each impulse of said given number into engagement with said line, means responsive to dialing both said predetermined number and said givennumber for-operating said last means to step said'wipers one step for each impulse in said predetermined number and one step for each impulse in the given number minusthenumber of impulses in said predetermined number thereby stepping said-wipers into engagement with said line by the same numberof steps as there are impulses. in said given number but by a different number of directive movements, and means for'selectively signaling either party'on said line dependent upon the call number dialed in extending the connection to said line.

10. In a telephone system, a line having-a twodigit call number, a test conductor for said line, a plurality of switches each having wipers and an associated switchbank, line bank contacts and a test bank contact in each switchbank correspond-,

ing to said line, a pair of normally open contacts;

in each switch, the first contact of said pair in each switch terminating said test conductor, the second contact of said pair in each switch-being connected to only the test bank contact in its associated switchbank, means for directively -operating the wipers of any one of said switches into engagement with said line and test bank contacts of said line in response to a calling subscriber dialing the first digit of said call number, and means in said one switch responsive to the calling subscriber dialing the second digit of said call number for operating the said pair of cone tacts in said one switch to connect said test con- 1 ductor to said test bank contact in the associated line having a test ing to said line, a pair of normally open contacts in each switch, the first contact of said pair in each switch terminating said test conductor, the second contact of said pair in each switch being connected to only the test bank contact in its associated switchbank, means for directively operating the test wiper of any one of said switches into engagement ,with the test bank contact in the switchbank associated with the operated switch, a relay in said one switch operated in response to said last operation, means in each switch for closing said pair of contacts, a circuit prepared for said last means in said one switch in response to said relay operation, and means for thereafter operating said last meansin said one switch over said prepared circuit to close said pair of contacts in said one switch to connect said test conductor to the said testbank contact inthe switchbank of saidone switch.

12. In a telephone system, a line having a test conductor, a plurality of automatic switches each having wipers and an associated switchbank, a test bank contact in each switchbank corresponding to said line, a pair of normally open contacts in each switch, the first contact of said pair in each switch terminating said test conductor, the second test contact of said pair in each switch being connected to only the test bank contact in its associated switchbank, means for directively operating the test Wiper of any -one of said switches into engagement with the test bank contact in the switchbank associated with the operated switch, a relay in said one switch operated in response to said last operation, means in each switch for closing said pair of contacts, a circuit prepared for said last means in said switch in response to said relay operation, means for thereafter operating said last means in said one switch over said prepared circuit to close said pair of contacts in said one switch to connect said test conductor to the said test bank contact in the switchbank of said one switch a source of signaling current in each switch, and means including said relay for connecting said source to said line.

13. In a telephone system, a line having a test conductor, a plurality of automatic switches each having a test bank contact in its switchbank corresponding to said line, a pair of normally open contacts in each switch, the first contact of said pair in each switch terminating said test conductor, the second contact of said pair in each switch being connected to only the test bank contact in its associated switchbank, and means in each switch for operating its pair of contacts to connect said test conductor of said line to said test bank contact in its associated switchbank.

14. In a telephone system, a line, a plurality of link circuits for completing connections to said line, a test conductor for said line common to all said link circuits, a pair of normally open contacts in each link circuit, the first contact of said pair in each link circuit terminating said test conductor, an individual test contact in each of said link circuits corresponding to said line, the second contact of said pair in each link circuit being individually connected to only the individual test contact in such link circuit, and means in each link circuit for operating its pair of con tacts to connect said common test conductor to the individual test contact of such link circuit.

15. In a telephone system, a line having a called number, a test conductor and a pair of line conductors for said line, a plurality of switches each having a test wiper, a pair of line wipers and an associated switchbank, means responsive to a calling subscriber dialing the first digit of said called number for directively operating said wipers of any one of said switches into engagement with the switchbanks corresponding to said line to connect only the pair of line wipers of said one switch with said pair of line conductors, and means in said one switch responsive to the calling subscriber dialing the second digit of said called number for connecting the test wiper of said one switch to the test conductor of said line.

16. In a telephone system, a first line, a second line, and a calling line, an automatic switch, means controlled by said calling line when calling the second line for directively operating said switch into engagement with said first line, and

for then directively operating it into engagement with said second line before releasing the switch, and means for transmitting a busy tone to the calling line in response to only the connection to the second line when the lines are both busy.

17. In a telephone system, a busy line, a called line, and a calling line, an automatic switch, means responsive to said calling line dialing the called number of said called line for directively operating said switch in a first directive operation into engagement with said busy line and then directively operating said switch in a second directive operation into engagement with said called line without releasing the switch, busy signaling means in said switch, and means for operating said busy signaling means to transmit a busy tone to the calling line in response to only the said second directive operation and then only in case the called line is busy.

18. In a telephone system, a first line, a second line, and a calling line, an automatic switch, means for operating said switch in one or two directively controlled operations into operative relation with either said first or said second line, busy signaling means in said switch for connecting a busy tone to the calling line, means for operating said busy signaling means only in case said switch has taken two directive operations in order to be operatively connected with said first line and then only in case said first line is busy, said signaling means also operated in case said switch has taken either one or two directive operations in order to be operatively con nected with said second line and then only in case said second line is busy.

19. In a telephone system, a forward operating nonreleasing switch having wipers and a single level of switchbank contacts for each wiper, a plurality of party lines terminating in sets of said switchbank contacts, means for directively operating said wipers into engagement with any set of said switch bank contacts, one set of said switchbank contacts terminating a given line and also used as a temporary stopping place for said wipers between dialed digits, a source of signaling current, means normally effective for connecting said source to a called line in one manner to signal a particular subscriber on the called line, and means operated in case said wipers were temporarily stopped on said one set of switchbank contacts during the establishment of a connection to a called line for reversing the connection of said source to such called line to signal a predetermined subscriber on such line.

FRANK KESSLER. 

